Inflammation and immune dysregulation have been linked to the pathogenesis and progression of Parkinson's disease (PD), and represent an attractive target for therapeutic intervention, given the potential for repurposing of existing anti-inflammatory and immunomodulatory agents. Despite the fact that initial studies of drugs with secondary anti-inflammatory effects did not yield positive results, agents specifically targeting immune and inflammatory pathways may hold more promise. This article will briefly review the evidence base for targeting the immune system and neuroinflammation in PD, and discuss in detail the recently completed and currently active trials of primary anti-inflammatory/immunomodulatory drugs in PD.
Keywords: Clinical trials; Parkinson’s disease; immune system; immunosuppressants; inflammasome; inflammation.
Parkinson’s disease is caused by a loss of dopamine-producing nerve cells in the brain. Recent research has suggested that activation of the immune system, leading to inflammation in the brain and body, can contribute to this loss. Current medications that are used to treat Parkinson’s disease only help with the symptoms, and do not slow down the damage to nerve cells in the brain. New treatments, aiming to reduce inflammation and thereby slow disease progression, are under investigation in a number of clinical trials which are reviewed in this article. These treatments include medications that have been used in other diseases, as well as new drugs designed to target inflammation and immune activation in PD. Some of these early studies have had encouraging results but further larger trials are needed to determine whether medications targeting inflammation will have benefit for people with PD.